Organic cranberry pomace and its ethanolic extractives as feed supplement in broiler: impacts on serum Ig titers, liver and bursal immunity.

With the pressure to reduce antibiotics use in poultry production, cost-effective alternative products need to be developed to enhance the bird's immunity. The present study evaluated the efficacy of cranberry fruit by-products to modulate immunity in broiler chickens. Broiler Cobb 500 chicks were fed a control basal diet, basal diet supplemented with bacitracin (BACI, 55 ppm), cranberry pomace at 1% and 2% (CP2), or cranberry pomace ethanolic extract at 150 and 300 ppm (COH300) for 30 d. Blood sera were analyzed at days 21 and 28 of age for Ig levels by ELISA. The innate and adaptive immune-related gene expression levels in the liver and bursa of Fabricius were investigated at 21 d of age by quantitative polymerase chain reaction arrays. At day 21, the highest IgY level was found in the blood serum of the CP2-fed birds. In the liver, 13 of the 22 differentially expressed genes were downregulated across all treatments compared with the control. Expression of genes belonging to innate immunity such as caspase 1 apoptosis-related cysteine peptidase, chemokine receptor 5, interferon gamma, myeloid differentiation primary response gene 88, and Toll-like receptor 3 were significantly downregulated mainly in BACI- and COH300-fed birds. In the bursa, 5 of 9 genes associated with the innate immunity were differentially expressed. The expression of anti-inflammatory IL-10 gene was upregulated in all treatment groups in bursa compared with the control. The expression of transferrin gene was significantly upregulated in livers of birds fed COH300 and in bursa of birds fed BACI, indicating feeding practices and organ-dependant modulation of this gene in broiler. Overall results of this study showed that cranberry product feed supplementation modulated the innate immune and suppressed proinflammatory cytokines in broilers, providing a platform for future investigations to develop berry products in poultry feeding.

Effects of the stems and leaves of Astragalus membranaceus on growth performance, immunological parameters, antioxidant status, and intestinal bacteria of quail.

This study was designed to evaluate the potential application of the stems and leaves of Astragalus membranaceus (AMSL) in the poultry industry. Quails were divided into four groups and fed daily with an AMSL-free diet (control) or with 1%, 3%, or 5% (w/w) AMSL-incorporated diets for 35 days. The results showed that supplementing AMSL in the diet, especially at a concentration of 3%, increased daily gain and feed intake during the entire experiment (p < 0.05). The immune organ development of the thymus and bursa of Fabricius was promoted, and the immune system was enhanced by increasing the quantities of IgA and complements C3 and C4 (p < 0.05). The total antioxidant capacity and the activities of glutathione peroxidase and catalase were increased (p < 0.05). Moreover, the 3%-5% AMSL groups regulated the intestinal flora by promoting the proliferation of lactic acid bacteria and inhibiting the growth of coliform bacteria (p < 0.05). In conclusion, feeding incorporated diets with appropriate AMSL levels significantly increased growth performance, strengthened the immune system, improved antioxidative status, and regulated the intestinal microflora of quails, suggesting that AMSL has the potential to serve as a feed additive in the poultry industry.

The Protective Role of Selenium in AFB1-Induced Tissue Damage and Cell Cycle Arrest in Chicken's Bursa of Fabricius.

Aflatoxin B1 (AFB1) is a naturally occurring secondary metabolites of Aspergillus flavus and Aspergillus parasiticus, and is the most toxic form of aflatoxins. Selenium (Se) with antioxidant and detoxification functions is one of the essential trace elements for human beings and animals. This study aims to evaluate the protective effects of Se on AFB1-induced tissue damage and cell cycle arrest in bursa of Fabricius (BF) of chickens. The results showed that a dietary supplement of 0.4 mg·kg-1 Se alleviated the histological lesions induced by AFB1, as demonstrated by decreasing vacuoles and nuclear debris, and relieving oxidative stress. Furthermore, flow cytometry studies showed that a Se supplement protected AFB1-induced G2M phase arrest at 7 days and G0G1 phase arrest at 14 and 21 days. Moreover, the mRNA expression results of ATM, Chk2, p53, p21, cdc25, PCNA, cyclin D1, cyclin E1, cyclin B3, CDK6, CDK2, and cdc2 indicated that Se supplement could restore these parameters to be close to those in the control group. It is concluded that a dietary supplement of 0.4 mg kg-1 Se could diminish AFB1-induced immune toxicity in chicken's BF by alleviating oxidative damage and cell cycle arrest through an ATM-Chk2-cdc25 route and the ATM-Chk2-p21 pathway.

Influence of Graded Levels of l-Theanine Dietary Supplementation on Growth Performance, Carcass Traits, Meat Quality, Organs Histomorphometry, Blood Chemistry and Immune Response of Broiler Chickens.

l-theanine is a water-soluble non-proteinous amino acid mainly found in green tea leaves. Despite the availability of abundant literature on green tea, studies on the use of l-theanine as a feed additive in animals, and especially broilers are limited. The objective of this study was, therefore, to evaluate the effect of different dietary levels of l-theanine on meat quality, growth performance, immune response, and blood metabolites in broilers. A total of 400 day-old broiler chicks were randomly divided into four treatment groups using a completely randomized design; C-control, basal diet; 100LT-basal diet + 100 mg l-theanine/kg diet; 200LT-basal diet + 200 mg l-theanine/kg diet; and 300LT-basal diet + 300 mg l-theanine/kg diet. Results revealed that the intermediate level of l-theanine (200 mg/kg diet) showed better results in terms of body weight gain (BWG), feed consumed (FC), and feed conversion ratio (FCR) as compared with the other supplemented groups and the control. The live weight eviscerated weight and gizzard weight were higher in all l-theanine levels as compared to those of the control group. Increased weight (p ≤ 0.05) of spleen and bursa were found in group 200LT (200 mg l-theanine/kg diet). Concerning meat color parameters, values for yellowness (b*), and redness (a*) were greater in l-theanine-supplemented groups than the control. Supplementing broiler diet with l-theanine reduced (p = 0.02) total serum cholesterol contents while increased HDL. Further analysis revealed lower relative serum cytokines (IL-2 and INF-γ) and reduced mRNA expression of TNF-α and IL-6 in thymus, and IFN-γ and IL-2 in spleen in the treated group. Moreover, supplementation with 200 mg/kg of l-theanine improved antioxidant status in blood by increasing SOD, GSH-Px, and relative CAT levels. It is concluded that the optimum supplementation level of l-theanine is 200 mg/kg of diet because it resulted in improved performance parameters in broilers. However, higher levels of l-theanine (300 mg/kg diet) may have deleterious effects on performance and health of broiler chickens.

Supranutritional dietary selenium depressed expression of selenoprotein genes in three immune organs of broilers.

The objective of this study was to investigate the effects of supranutritional dietary selenium (Se) on selenoproteins expression in three immune organs of chickens. A total of 160 1-day-old male Cobb broilers were randomly divided into two groups and fed a Se-deficient corn-soybean basal diet supplemented with 0.3 (adequate) and 3.0 (excess) mg/kg Se for 42 days. Immune organs were collected, and effects of supranutritional Se on messenger RNA abundance of 23 selenoprotein genes and eight inflammation-related genes were compared at day 42. Also enzyme activities were measured at days 14, 28 and 42. The results showed supranutritional dietary Se depressed growth performance of chicken and down-regulated nine and three selenoprotein genes in thymus and spleen, respectively, and only Sepp1 was up-regulated in the bursa of Fabricius. Also three, three and seven inflammation-related genes were up-regulated in three organs, respectively. Supranutritional Se elevated (P < 0.05) activities of superoxidase dismutase, total antioxidant capacity and glutathione peroxidase, mainly in early stages. In summary, supranutritional Se resulted in down-regulation of selenoprotein genes and up-regulation of inflammation-related genes in three immune organs of chicken, which indicated potential roles of those selenoprotein genes in immune organs of the chicken.

Selenium Deficiency Induces Autophagy in Immune Organs of Chickens.

The aim of the present study was to investigate the effects of selenium (Se) deficiency on autophagy-related genes and on ultrastructural changes in the spleen, bursa of Fabricius, and thymus of chickens. The Se deficiency group was fed a basal diet containing Se at 0.033 mg/kg and the control group was fed the same basal diet containing Se at 0.15 mg/kg. The messenger RNA (mRNA) levels of the autophagy genes microtubule-associated protein 1 light chain 3 (LC3)-I, LC3-II, Beclin 1, dynein, autophagy associated gene 5 (ATG5), and target of rapamycin complex 1 (TORC1) were assessed using real-time qPCR. The protein levels of LC3-II, Beclin 1, and dynein were investigated using western blot analysis. Furthermore, the ultrastructure was observed using an electron microscope. The results indicated that spleen mRNA levels of LC3-I, LC3-II, Beclin 1, dynein, ATG5, and TORC1 and the protein levels of LC3-II, Beclin 1, and dynein were increased in the Se deficiency group compared with the control group. In the bursa of Fabricius, the mRNA levels of LC3-I, LC3-II, Beclin 1, dynein, ATG5, and TORC1 and the protein levels of Beclin 1 and dynein were increased; furthermore, the protein level of LC3-II was decreased in the Se deficiency group compared to the control group. In the thymus, the mRNA levels of LC3-I, Beclin 1, and ATG5 increased; the levels of LC3-II, dynein, and TORC1 were decreased; the protein level of Beclin 1 increased; and the levels of LC3-II and dynein decreased in the Se deficiency group compared to those in the control group. Further cellular morphological changes, such as autophagy vacuoles, autolysosomes, and lysosomal degradation, were observed in the spleen, bursa of Fabricius, and thymus of the Se-deficiency group. In summary, Se deficiency caused changes in autophagy-related genes, which increased the autophagic process and also caused structural damages to the immune organs of chickens.

Selenium Deficiency Mainly Influences Antioxidant Selenoproteins Expression in Broiler Immune Organs.

Selenoprotein has many functions in chicken, and the expression of selenoproteins is closely associated with the selenium (Se) level. However, little is known about the expression patterns of selenoproteins in chicken immune organs. Here, we investigated the effect of dietary Se deficiency on the expressions of 23 selenoproteins in broiler immune organs. In this study, 150 broilers were randomly divided into two groups (75 chickens per group). The chickens were maintained either on a diet supplemented with Se through the addition of 0.2 mg/kg of Se (C group) via sodium selenite or on a Se-deficient granulated diet (L group) until the broilers exhibited an onset of exudative diathesis (ED). Following euthanasia, the samples from the immune tissues (including the spleen, thymus, and bursa of Fabricius) were quickly collected, and the messenger RNA (mRNA) expression levels of 23 selenoproteins were examined by real-time quantitative PCR and analyzed using principal component analysis. The results showed that Se deficiency decreased the mRNA levels of 23 selenoproteins in the thymus, spleen, and bursa of the Fabricius tissues of broiler chickens. Furthermore, we found that among 23 selenoproteins, the mRNA levels of Dio1 in the thymus, Txnrd2 in the spleen, and Txnrd3 in the bursa of Fabricius decreased significantly (90.9 %, 83.3 %, and 96.8 %, respectively). In addition, the principal component analysis (PCA) results suggested that Se deficiency mainly influenced the expression of antioxidative selenoproteins, especially glutathione peroxidases (Gpxs), thioredoxin reductases (Txnrds), and iodothyronine deiodinases (Dios) in chicken immune organs. The results of this study are valuable for understanding the relevance of selenoprotein activity in vivo.

Selenium and Polysaccharides of Atractylodes macrocephala Koidz Play Different Roles in Improving the Immune Response Induced by Heat Stress in Chickens.

The aim of the present study was to investigate the effect of acute heat stress (HS) on the chicken immune response and to examine the role of selenium (Se) and the polysaccharides of Atractylodes macrocephala Koidz (PAMK) in immune regulation in the chicken immune system. Two hundred chickens were randomly divided into two groups: the HS group and the control (Con) group. These chickens were treated with Se (0.3 mg/kg), PAMK (200 mg/kg) alone, and a combination of Se (0.3 mg/kg) and PAMK (200 mg/kg). The cytokines; antioxidative enzymes; and HSP60, HSP70, and HSP90 levels were examined in chicken immune organs. The results indicated that HS-induced immune dysfunction included increased levels of TNF-α, IFN-γ, IL-2, IL-4, HSP60, HSP70, HSP90, and malondialdehyde (MDA) as well as decreased levels of glutathione peroxidase (GPx) and superoxide dismutase (SOD) in immune organs (P < 0.05). Among the affected organs, the bursa of Fabricius was one primary target of HS. The immune dysfunction induced by HS was alleviated (P < 0.05 or not) by treatment with Se and PAMK in different immune organs. However, Se only regulated the expression of TNF-α and IFN-γ, and PAMK influenced more cytokines in immune organs. The results showed that Se specifically regulated the TNF-α and IFN-γ pathways. Therefore, Se and PAMK played different roles in improving the immune response in HS chicken.

Lycopene reduces the negative effects induced by lipopolysaccharide in breeding hens.

This study assessed the effects of lycopene on the antioxidant capacity, biochemical parameters, and immune organ index of breeding hens following lipopolysaccharide (LPS) injection. The study had a 2 × 2 factorial design. Healthy Xing-hua breeding hens (720) were divided into groups with 6 replicates per group and 30 hens per replicate. Hens were fed on a rice-soya bean basal meal supplemented with different levels of lycopene (0, 20, 40, or 80 mg/kg diet). On d 35, two hens from each replicate were injected subcutaneously with 1 mg/kg body weight of either LPS or sterile saline (control group). Blood samples were collected at 0, 6, and 24 h post-injection. At 24 h post-injection, hens were sacrificed and the thymus, spleen, and bursa of Fabricius were removed. The results revealed that LPS significantly decreased high density lipoprotein cholesterol (HDLC), triidothyronine (T3), reduced glutathione to oxidised glutathione ratio (GSH/GSSG), thymus and bursal indexes, and increased low density lipoprotein cholesterol (LDLC). Lycopene supplementation significantly increased HDLC, T3, GSH/GSSG, and immune organ index, and decreased total cholesterol, LDLC, and blood urea nitrogen (BUN). The interaction effects of lycopene and LPS were significant on BUN and T3. Lycopene supplementation affected inflammatory immune response based on increased immune organ index of breeding hens by relieving the LPS-induced stress.

Immune-modulatory effects of dietary Saccharomyces cerevisiae cell wall in broiler chickens inoculated with Escherichia coli lipopolysaccharide.

1. An experiment was conducted to study the effect of yeast (Saccharomyces cerevisiae) cell wall (YCW) supplemented in diets of broiler chickens challenged with Escherichia coli lipopolysaccharide (LPS). 2. One-day-old broiler chicks were randomly distributed into 24 cages (6 replicate cages; 8 birds/cage) and were inoculated with 0 or 1 mg/kg body weight E. coli-LPS (d 4 and 9) and 0 or 500 mg YCW/kg feed, resulting in a 2 × 2 factorial arrangement of treatments. Experimental diets did not include coccidiostats, in-feed antibiotics or enzymes. 3. On d 21, the inoculation of E. coli-LPS reduced weight gain and feed intake and increased feed conversion ratio (FCR) of birds, an effect maintained until 28 d. In contrast, chickens given diets with YCW improved the FCR at both 21 and 28 d of age. 4. E. coli-LPS challenge reduced the relative weight of bursa of Fabricius, except when chickens were given YCW, which resulted in an interaction. Supplementation of broiler diets with YCW exacerbated the cellular immune response as measured by the delayed cutaneous hypersensitivity response test. 5. The results of this study suggested a benefit on feed efficiency when YCW was added to diets fed to broiler chickens challenged with E. coli-LPS. Part of the mode of action of YCW might be related to better maintenance of immune status in response to microbial challenge.

Effects of yeast cell walls on performance and immune responses of cyclosporine A-treated, immunosuppressed broiler chickens.

The present study was conducted to investigate the effects of dietary yeast (Saccharomyces cerevisiae) cell walls (YCW) from the yeast extract industry on performance and immune function of cyclosporine A (CSA)-treated, immunosuppressed broiler chickens. A total of 240 day-old male broilers were allocated randomly into four treatments: (1) non-challenged control; (2) non-challenged control+0·3 % YCW; (3) CSA-challenged group; (4) CSA-challenged+0·3 % YCW. On days 1-4 and 22-25 of age, broilers were subcutaneously injected with CSA or sterile saline. The results showed that supplementation of YCW significantly improved daily weight gain (DWG) during the starter (days 1-21, P < 0·01), finisher (days 22-42, P < 0·01) and overall (days 1-42, P < 0·05) periods compared with the control birds, but had no effect on feed conversion ratio (FCR, P>0·05). Compared with the CSA-treated birds, YCW alleviated the decrease of DWG (P < 0·01) and increase of FCR (P < 0·05) caused by CSA challenge at different periods and cumulatively. On days 21 and 42, YCW mitigated the CSA-induced decrease of peripheral blood lymphocyte blastogenic response (P < 0·01). In addition, YCW improved the relative weights of the bursa of Fabricius (P < 0·01) and thymus (P < 0·01) and up-regulated the splenic expression of pro-inflammatory cytokines IL-1ß (P < 0·01) and IL-6 (P < 0·01) on day 42 compared with the CSA-treated birds. These results indicate that YCW supplementation has beneficial effects in attenuating the immunosuppressive effects of CSA challenge, therefore improving growth performance of broiler chickens.

In vivo immunomodulatory effects of dietary purple sweet potato after immunization in chicken.

This study was intended to determine the modulatory effects of dietary supplementation of purple sweet potato (Ipomoea batats Poir., PSP) on the immune response of chickens. PSP was included in a basal starter diet by 1% (PSP(L)) or 3% (PSP(H)) and continually fed. Newcastle disease (NDV) vaccine, Brucella abortus (BA) and sheep red blood cells (SRBC) were used for chicken immunization. Antibody titers against these antigens were used to estimate humoral immunity. Concanavalin A (Con A)-induced proliferations of splenocytes, thymocytes and peripheral blood lymphocytes (PBL), ratios of CD4- and CD8-single positive and CD4-CD8-double negative (DN) cells in splenocytes, were both used to indicate cellular immunity. Relative weights of spleen, thymus and bursa and white blood cell (WBC) counts were studied. PSP(H) increased anti-NDV (P < 0.05), anti-BA (P < 0.01) and anti-SRBC titers (P < 0.05) in response to secondary immunization, whereas PSP(L) increased titers of anti-BA (P < 0.05) and anti-SRBC (P < 0.01). Proliferations of splenocytes and thymocytes were augmented with PSP(L) (P < 0.05). PSP(H)-treated chickens had lower (P < 0.05) ratios of CD4-single positive lymphocytes. Proliferation of PBL, weights of lymphoid organs and WBC counts were not affected. These results suggest that dietary PSP supplementation could enhance the immune response after immunization in chickens.

Direct enhancement of the phagocytic and bactericidal capability of abdominal macrophage of chicks by beta-1,3-1,6-glucan.

Salmonella enterica serovar Enteritidis is the major zoonotic and intracellular pathogen. Different strategies have been developed to prevent the S. Enteritidis infection. The beta-1,3-1,6-glucan of Schizophyllum commune was used as an immunological booster to determine the minimal dietary level of beta-glucan that would restrict S. Enteritidis infection through the effects of beta-glucan on the activity of macrophages and direct physical protection of the intestine. One-day-old male Single Comb White Leghorn chicks were used in all trials. In trials 1 and 2, the 0.1% beta-1,3-1,6-glucan treatment completely eliminated the viable S. Enteritidis from spleen and liver in an oral challenge of 10(8) S. Enteritidis without any harmful effect on BW, serum proteins, and immunoglobulin. Instead of a 21-d feeding period of beta-glucan, a 14-d treatment was enough to eliminate the S. Enteritidis in spleen and liver. In trial 3, an increase in the relative weight of bursa of Fabricius and phytohemagglutinin-P-inducing cutaneous basophil hypersensitivity was observed (P < 0.05). In trials 2, 3, and 4, the direct or indirect effect of beta-1,3-1,6-glucan on abdominal macrophages was examined. Sterilized 3% Sephadex G-50 was injected to induce abdominal (peritoneal) phagocytes in chicks fed with or without 0.1% beta-1,3-1,6-glucan. Significantly increased phagocytic and bactericidal capability to S. Enteritidis was found in abdominal macrophages either pretreated or in vitro treated with 0.1% beta-1,3-1,6-glucan. In conclusion, in addition to the physical properties to block S. Enteritidis entrance, 0.1% dietary beta-1,3-1,6-glucan may enhance the host defense to S. Enteritidis by directly upregulating the phagocytosis and bactericidal activity of abdominal macrophages in chicks.

Evaluation of homeopathy in broiler chickens exposed to live viral vaccines and administered Calendula officinalis extract.

BACKGROUND: In this study it was determined that a Calendula officinalis water extract can reduce the immune response to three different viruses in broiler chickens, associated with improvement in body weights. MATERIAL/METHODS: The experiment was conducted on broiler chickens divided into two groups of 105 birds each. The first group received a Calendula officinalis water extract orally, while the second group received drinking water only. All birds in the two groups were similarly exposed to three different live vaccine viruses. Quantitative assessment of humoral immunity to each of the 3 viruses and records of bursal and thymus weight indices were taken. Performance, as observed in weight records at 21 and 41 days of age, feed conversion, and% mortality up to market age, was also evaluated. RESULTS: There was a reduction in immune response to IB virus at 42 days of age, to ND virus at 29 and 42 days of age, and to IBD virus at 14, 29, and 42 days of age in the Calendula officinals-treated birds in comparison with controls. This immune reduction in Calendula officinalis-treated birds was associated with insignificant reduction in the bursal weight index at 42 days of age and an improvement in mean weights at 21 and 41 days of age; the feed conversion and mortality rates were similar in the two groups (P>0.05). CONCLUSIONS: Calendula officinalis had an immunomodulation effect against three different live viruses in broiler chickens.

Effects of Chinese herbal polysaccharides on the immunity and growth performance of young broilers.

Two trials were conducted to study the effects of two Chinese herbal polysaccharides [achyranthan (ACH), a low-molecular-weight polysaccharide, and astragalan (APS), a high-molecular-weight polysaccaride] on the immunity and growth performance of young broilers. Trial 1 was a 28-d growth assay, in which 7-d-old broilers (n = 240) were randomly allotted to one of three dietary treatments, with eight replicate pens per treatment and ten chickens per pen. Dietary treatments included a control corn-soy-fishmeal (Treatment 1), a diet with 200 mg/kg APS (Treatment 2), and a diet with 200 mg/kg ACH (Treatment 3). Blood samples were collected by cardiac puncture on Days 7, 14, 21, and 28 for determination of serum parameters, and chickens were killed on Day 28 to measure immune organ indexes. Trial 2 was an in vitro trial to study the effects of different concentrations of polysaccharides on broiler splenocyte functions. In Trial 1, feeding either APS or ACH had no significant effects on growth performance of broilers relative to the control. However, compared to the control, feeding ACH significantly increased microhemagglutination inhibition (HI) antibody titers, bursa of Fabricius index, serum albumin, serum calcium, and nitric oxide (NO) concentrations at Day 28 (P < or = 0.05). In Trial 2, both polysaccharides showed significant immunostimulating effects. They increased NO and interleukin-2 (IL-2) production of splenocytes and enhanced splenocyte proliferation in a dose-dependent manner (P < 0.05). Those results indicate that the immunostimulating effects of APS are not as pronounced as those of ACH. Achyranthan showed immunostimulating effects in both the growth assay and in vitro studies. Therefore, ACH may be a Chinese herbal polysaccharide that has the potential to be used as a feed additive to improve broilers' immunity.

Effect of ascorbic acid supplementation on the immune response of chickens vaccinated and challenged with infectious bursal disease virus.

One-day-old chickens were divided into two groups and reared under similar conditions. One group was fed a diet supplemented with 1000ppm ascorbic acid and the other group was fed an identical diet, but not supplemented with ascorbic acid. Both groups were vaccinated against infectious bursal disease (IBD) at 7 days of age and challenged orally with 4x10(5) of 50% embryo-lethal-dose IBDV 14 days later. The number of anti-IBDV antibody secreting cells, production of interleukin-2 (IL-2) by splenocytes, number of CD4(+), CD8(+) and IgM(+) cells in spleen and IgM(+) cells in bursa of Fabricius were compared between the two groups at 7 days (prior to vaccination), 21 days (14 days post-vaccination and prior to challenge) and 31 days (10 days post-challenge) of age. The number of CD8(+) in spleen at 7 days of age and IgM(+) cells in bursa at 7, 21 and 31 days of age were significantly higher in ascorbic acid supplemented group (P<0.05). Production of IL-2 by splenocytes was higher as indicated by higher stimulation indices in ascorbic acid supplemented group. The number of anti-IBDV IgG antibody secreting cells in spleen at 21 and 31 days of age were significantly higher in ascorbic acid supplemented group (P<0.05). Dietary supplementation of ascorbic acid may ameliorate the immunosuppression caused by IBDV vaccination and improve humoral and cellular immune responses.

BASH, a novel signaling molecule preferentially expressed in B cells of the bursa of Fabricius.

The bursa of Fabricius is a gut-associated lymphoid organ that is essential for the generation of a diversified B cell repertoire in the chicken. We describe here a novel gene preferentially expressed in bursal B cells. The gene encodes an 85-kDa protein, designated BASH (B cell adaptor containing SH2 domain), that contains N-terminal acidic domains with SH2 domain-binding phosphotyrosine-based motifs, a proline-rich domain, and a C-terminal SH2 domain. BASH shows a substantial sequence similarity to SLP-76, an adaptor protein functioning in TCR-signal transduction. BASH becomes tyrosine-phosphorylated with the B cell Ag receptor (BCR) cross-link or by coexpression with Syk and Lyn and associates with signaling molecules including Syk and a putative chicken Shc homologue. Overexpression of BASH results in suppression of the NF-AT activation induced by BCR-cross-linking. These findings suggest that BASH is involved in BCR-mediated signal transduction and could play a critical role in B cell development in the bursa.

Humoral immunity in chicks experiencing marginal vitamin B-6 deficiency.

An economical vitamin B-6-deficient ration that was palatable to broiler chickens was prepared and fed to 1-day-old chicks. The experimental ration was a typical soy-glucose ration. Vitamin B-6 was removed by washing the soybean meal with water. Microbiological analysis revealed that the washed ration contained 0.45 mg vitamin B-6 per kilogram. Experimental rations were formulated to contain 0.5, 1.0 and 3.0 mg supplemental pyridoxine x HCl per kilogram of ration. These supplemental levels produced the following total pyridoxine concentrations in the diet: 0.95, 1.48 and 3.18 mg pyridoxine x HCl activity per kilogram of diet. Chicks were grown to 7 weeks of age and characteristic vitamin B-6 deficiency signs were quantitated and/or observed. Notable signs in chicks receiving 0.5 mg added vitamin B-6 were increased mortality, decreased body weight gain and increased incidence of abnormal leg conformation. The humoral immune system of broiler chicks that were moderately deficient in vitamin B-6 was investigated. Marginal pyridoxine deficiency caused significant reduction in antibody levels to sheep red blood cells (SRBC) and relative levels of IgM and IgG during the peak and degradation phases of the primary response. During the hyperimmune response total anti-SRBC levels were not affected; however, relative levels of IgM and IgG were lowered.

Experimental fowl typhoid in chicks impaired immunologically by treatment with cyclophosphamide.

Male chicks were injected intramuscularly with 6 mg of cyclophosphamide daily for three consecutive days, the initial dose being given on the day of hatching. This treatment impaired bursal development and lymphopoiesis and no circulating antibodies appeared after such chicks were injected with Salmonella gallinarum antigens at 19 and again at 26 days of age. In impaired chicks which were infected orally when 15 days old with S gallinarum the level of mortality was essentially the same as that in unimpaired animals. Impairment did not affect the lower mortality that accompanies feeding with a nutritionally adequate diet containing meat meal as the sole protein supplement in comparison with fish meal as the supplement. An anaemia was present in chicks examined seven days after infection. This anaemia was microcytic to a degree that either exceeded or approached statistical significance. As antibody-mediated hypersensitivity reactions involving the erythrocytes were absent in the impaired chicks, the anaemia must have differed in pathogenesis from the macrocytic anaemia of immunopathological orgin reported by others in adult females with acute fowl typhoid. A disturbance of iron metabolism could have accounted for the anaemia in the diseased chicks.